Device for swaging screw-threads on eyebolts



5o scale-groove, g, which keeps the UNITED STATES PATENT OFFICE,

THOMAS BURKE, OF PORTSMOUTH, VIRGINIA.

DEVICE FOR SWAGING SCREW-THREADS ON EYEBOLTS.

SPECIFICATION forming part of Letters Patent No. 228,033, dated May 25,l 1880. Application led November 1B, 1879.

To all whom it may concern Be lit known that I, THOMAS BURKE, of Portsmouth, in the county of Norfolk and State of Virginia, have invented a new and valuable Improvement in Hot-Metal Screw- Gutters and Eyebolt-Formers; and I do hereby declare that the following is a full, clear, and exact description ot' the construction and operation of the same, reference being had to the annexed drawings, making' a part of this specification, and to the letters and figures of reference marked thereon.

Figure 1 of the drawings is a representation of a vertical4 central section of this invention. Fig. 2 :is a vertical transverse section of the same. Fig. 3 is a horizontal section of the bed-die and circumscribing band. Fig. L,Lisa bottom view of the slide-die, and Fig. 5 is a perspective view of the eyebolt.

This invention has relation to an improved means for forming the threaded portions of bolts, especially eyebolts, designed to be subjected to great strain; and it consists in the construction and novel arrangement of parts, as hereinafter shown, described. and particularly pointed out in the claim.

In the accompanying drawings, the letterA designates the bed-die, which is rectangular in plan, having a bifurcated form vertically, its upright side walls or branches, Il, having their inner and outer surfaces all parallel, as shown in the drawings.

The score of the bed-die is formed between the branches b at their lower ends, and connects therewith by horizontal shoulders c, which form stops for the end of the upper or movable die, D, which slides between the branches b of said bed-die. This slide-die is of rectangular plan, and its scored sides are ush with the edge c of the branches of the bed-die.

The die-surfaces are tapered slightly from the entrance to the other end in order to form a tapered screw. The die-surfaces are not full semicircles, but arcs of about one-third the circumference, so that they have a somewhat iiattened or elliptical appearance when the die-stops are in contact. Along the lowermost portion of the bed-die score is a deep scores clear.

lrectangular in form and The bed die is usually provided with a square tang or projection, t, whereby it may be attached to an anvil or other bed-block, and the slide-die extends above the branches of the bed-dica sufficient distance to form a handle, h, the upper end of which is squared, as shown at k, to receive the strokes of the hammer. Y

L represents a circumscribing guide-box, open at each end. This is slipped over the branches of the beddie, and forms the main guide for the slide-die as it is moved up and down in its operation. This guide-box is provided with circular openings m at the ends of the die-scores, the centers of said openings being in line with the centers of the arcsof the die-scores.

The dies are made of best steel, and are designed to work on a heated rod, so as to preserve the outer fibrous formation, the thread being formed, by hammering, with the slide-die as the rod is turned, the box serving to guide the work and to keep the dies in line, as well as to prevent the branches of the bed-die from spreading.

This improvement is especially designed for the construction of eyebolts used in lumber-hauling, as itis essential that such bolts should have great strength in the threaded portion and be easily removed from the wet logs.

I am aware that the dies themselves, their mode of operation, and the results of their use are not new, and I do not claim them; but

I do claim as my improvement- Jointly with the dies, the groove g, -the open-ended box or sleeve L, and the broad, plain, and parallel-faced side walls or branches, b, in virtue of which obstruction of the dies by scale is prevented and the hammer-die is accurately guided in its movements, substantially as specied.

In testimony that I claim hereunto subscribed of two witnesses.

the above I have my name in the presence THOMAS BURKE.

Witnesses:

V. A. HAYNEs, C. W. HIGGINS. 

